Display device

ABSTRACT

According to one embodiment, a display device includes a first insulating layer, a first source line and a second source line, an organic insulating layer including a contact hole, a drain electrode located on the first insulating layer and exposed from the organic insulating layer in the contact hole, a conductive material covering the drain electrode in the contact hole, a second insulating layer located on the organic insulating layer, and a pixel electrode located above the second insulating layer and in the contact hole, and electrically connected to the drain electrode, the conductive material being in contact with the first insulating layer exposed from the organic insulating layer in the contact hole.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a Continuation Application of PCT Application No.PCT/JP2019/027825, filed Jul. 12, 2019 and based upon and claiming thebenefit of priority from Japanese Patent Application No. 2018-146127,filed Aug. 2, 2018, the entire contents of all of which are incorporatedherein by reference.

FIELD

Embodiments described herein relate generally to a display device.

BACKGROUND

Recently, as the virtual reality (VR) becomes more widely popular, thereis an increasing demand for super high-definition display devices. Thesuper high-definition display devices comprise pixels whose sizes aresmaller as compared to those of the conventional display devices.Therefore, a portion covered by an insulating layer or the like in aconventional display device can be exposed from the insulating layer orthe like in a super high-definition display device.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective diagram showing an example of an appearance of aliquid crystal display device according to the first embodiment.

FIG. 2 is a plan view schematically showing a first substrate accordingto the first embodiment.

FIG. 3 is a plan view showing a second electrode of the first substrateaccording to the first embodiment.

FIG. 4 is a cross-sectional view of a display panel taken along line A-Ain FIG. 3.

FIG. 5 is a cross-sectional view of the display panel taken along lineB-B in FIG. 3.

FIG. 6 is a cross-sectional view of the display panel taken along lineC-C in FIG. 3.

FIG. 7 is a cross-sectional view of the display panel taken along lineD-D in FIG. 3.

FIG. 8 is a cross sectional view of a display panel according to anotherconfiguration example of the display device of the first embodiment.

FIG. 9 is a cross sectional view of a display panel according to stillanother configuration example of the display device of the firstembodiment.

FIG. 10 is a cross sectional view of a display panel according to stillanother configuration example of the display device of the firstembodiment.

DETAILED DESCRIPTION

In general, according to one embodiment, a display device comprises afirst insulating layer, a first source line and a second source linelocated on the first insulating layer and arranged with an intervaltherebetween, an organic insulating layer located on the firstinsulating layer, the first source line and the second source line andcomprising a contact hole, a drain electrode located on the firstinsulating layer between the first source line and the second sourceline and exposed from the organic insulating layer in the contact hole,a conductive material covering the drain electrode in the contact hole,a second insulating layer located on the organic insulating layer and apixel electrode located above the second insulating layer and in thecontact hole, and in direct contact with the conductive material andelectrically connected to the drain electrode, and the conductivematerial being in contact with the first insulating layer exposed fromthe organic insulating layer between the organic insulating layer andthe drain electrode in the contact hole.

According to another embodiment, a display device comprises a firstinsulating layer, a first source line and a second source line locatedon the first insulating layer and arranged with an intervaltherebetween, an organic insulating layer located on the firstinsulating layer, the first source line and the second source line andcomprising a contact hole, a drain electrode located on the firstinsulating layer between the first source line and the second sourceline and comprising a first end portion on a side of the first sourceline exposed from the organic insulating layer in the contact hole and asecond end portion on a side of the second source line and a conductivematerial covering the first end portion and the second end portion inthe contact hole, a second insulating layer located on the organicinsulating layer and a pixel electrode located on the second insulatinglayer and in the contact hole, in direct contact with the conductivematerial, and electrically connected to the drain electrode.

According to still another embodiment, a display device comprises: afirst insulating layer; a first source line and a second source linelocated on the first insulating layer and arranged with an intervaltherebetween; an organic insulating layer located on the firstinsulating layer, the first source line and the second source line andcomprising a contact hole; a drain electrode located on the firstinsulating layer between the first source line and the second sourceline and exposed from the organic insulating layer in the contact hole;a conductive material covering the drain electrode in the contact hole;a second insulating layer located on the organic insulating layer; apixel electrode located on the second insulating layer and electricallyconnected to the drain electrode; a first electrode located between theorganic insulating layer and the second insulating layer; and a firstmetal wiring line overlapping the first source line and in contact withthe first electrode, the conductive material being in contact with thefirst insulating layer exposed from the organic insulating layer betweenthe organic insulating layer and the drain electrode in the contacthole, and the conducting material containing at least one of a firstmaterial same as that of the first electrode and a second material sameas that of the first metal wiring line.

Embodiments will be described hereinafter with reference to theaccompanying drawings. The disclosure is a mere example, and arbitrarychange of gist which can be easily conceived by a person of ordinaryskill in the art naturally falls within the inventive scope. To moreclarify the explanations, the drawings may pictorially show width,thickness, shape and the like, of each portion as compared with anactual aspect, but they are mere examples and do not restrict theinterpretation of the invention. In the present specification anddrawings, elements like or similar to those in the already describeddrawings may be denoted by similar reference numbers and their detaileddescriptions may be arbitrarily omitted.

In the embodiments, a display device is disclosed as an example of theelectronic devices. This display device can be used for various kinds ofdevices, for example, a virtual reality (VR) viewer, a smartphone, atablet terminal, a portable telephone terminal, a notebook computer, agame console and the like.

FIG. 1 is a perspective diagram showing an example of an appearance ofthe liquid crystal display device DSP according to the first embodiment.A first direction X, a second direction Y, and a third direction Z areorthogonal to each other, but may intersect at an angle other thanninety degrees. The first direction X and the second direction Ycorrespond to a direction parallel to a main surface of a substratewhich constitutes a liquid crystal display device (to be referred tosimply as a display device) DSP, and the third direction Z correspondsto the thickness direction of the display device DSP. Here, a plane viewof the display device DSP in an X-Y plane defined by the first directionX and the second direction Y is illustrated. In the followingdiscussion, a plan view means that an X-Y plane is viewed from the thirddirection Z.

The display device DSP comprises a display panel PNL and an illuminationdevice BL.

The display panel PNL comprises a first substrate SUB1, a secondsubstrate SUB2 opposing the first substrate SUB1 and a liquid crystallayer, which is a liquid crystal layer LC described below) held betweenthe first substrate SUB1 and the second substrate SUB2. Further, thedisplay panel PNL comprises a display area DA and a non-display areaNDA. The display area DA is an area which displays images. The displayarea DA is located in substantially a center of a region where the firstsubstrate SUB1 and the second substrate SUB2 oppose each other. Thenon-display area NDA is an area where images are not displayed, and islocated outside the display area DA.

The first substrate SUB1 comprises a connection portion CN. Theconnection portion CN comprises terminals for connecting signal supplysources such as a flexible printed-circuit board, IC chip and the like.The connection portion CN is located in the non-display area NDA.

The illumination device BL is disposed on a rear surface side (anopposite side of the surface opposing the second substrate SUB2) of thefirst substrate SUB1. As such an illumination device BL, various kindsof forms are applicable. For example, the illumination device BLcomprises a light guide opposing the first substrate SUB1, a pluralityof light sources such as light emitting diodes (LEDs), disposed along anend portion of the light guide, a reflective sheet disposed on a mainsurface side of the light guide, and various optical sheets stacked onanother main surface side of the light guide and the like.

Note that the display panel PNL of the illustrated example is of atransmissive type which displays images by selectively transmittinglight from the illumination device BL, but it is not limited to this.For example, the display panel PNL may be a reflective type whichdisplays images by selectively reflecting external light or light fromon external light source or may be a transreflective type provided forboth transmissive and reflective display functions.

Further, a detailed explanation of the configuration of the displaypanel PNL is omitted here, but any one of a display mode which uses avertical electric field along a normal of the display panel PNL, adisplay mode which uses an inclined electric field inclined along thenormal of the display panel PNL and a display mode which uses a lateralelectric field along the main surface of the display panel PNL is alsoapplicable.

In this embodiment, a direction from the first substrate SUB1 towardsthe second substrate SUB2 is defined as an upward direction (or, simply,up) and a direction from the second substrate SUB2 towards the firstsubstrate SUB1 is defined as a downward direction (or simply, down).

FIG. 2 is a plan view schematically showing the first substrate SUB1according to the first embodiment. FIG. 2 shows a main portion of thefirst substrate SUB1. Here, a configuration example in which a fringefield switching (FFS) mode, which is one of the display modes which usethe lateral electric field will be described.

The first substrate SUB1 comprises a plurality of gate lines G (G1, G2,G3, . . . ), a plurality of light-shielding layers LS, a plurality ofsource lines S (S1, S2, S3, S4, . . . ), switching elements SW, drainelectrodes RE, pixel electrodes PE, electrically-conductive materialsCM, metal wiring lines MT, first electrodes E1, second electrodes E2 andthe like. Note that FIG. 2 shows only the part of the configurationnecessary for the explanation, and the illustration of the secondelectrodes E2 and the like is omitted.

The plurality of gate lines G (G1, G2, G3, . . . ) are arranged alongthe second direction Y with predetermined intervals therebetween. Theplurality of gate lines G (G1, G2, G3, . . . ) each extend along thefirst direction X and are formed into a linear manner. Note that thegate lines G (G1, G2, G3, . . . ) may be partially bent. The gate linesG (G1, G2, G3, . . . ) are of, for example, molybdenum-tungsten alloyfilm. In plan view, the gate lines G overlap the light-shielding layersLS, respectively.

The plurality of source lines S (S1, S2, S3, S4, . . . ) are arrangedalong the first direction X with predetermined intervals therebetween.The source lines S (S1, S2, S3, S4, . . . ) each extend along the seconddirection Y. Note that the source line S (S1, S2, S3, S4, . . . ) may bepartially bent. The source lines S (S1, S2, S3, S4, . . . ) are of, forexample, a three-level stacked film of titanium/aluminum/titanium, athree-level stacked film of aluminum/titanium/aluminum, or the like. Inthe drawings, each subpixel PX is equivalent to a region sectioned byeach adjacent pair of gate lines G and each respective adjacent pair ofsource lines S. For example, each subpixel PX is equivalent to a regionsectioned by a gate line G1 and a gate line G2, and a source line S1 anda source line S2.

The light-shielding layers LS respectively overlap the gate lines G andare arranged along the respective gate lines G with intervalstherebetween along the first direction X. In other words, thelight-shielding layers LS overlap the gate lines G and are arranged inan island manner along the gate lines G. In the example illustrated, thelight-shielding layers LS each overlap the respective gate line Gbetween two source lines S adjacent to each other along the firstdirection X. Note that the light-shielding layers LS each may be formedlinearly to extend in the first direction X along the gate lines G (G1,G2, G3, . . . ), respectively. Further, the light-shielding layers LSmay be partially bent. The light-shielding layers LS are formed of, forexample, a molybdenum-tungsten alloy. In the example illustrated, thewidth of the light-shielding layers LS along the second direction Y isgreater than the width of the gate lines G along the second direction Y.

A switching element SW is disposed in each subpixel PX. The switchingelement SW is electrically connected to the respective gate line G andthe respective source line S. In the example illustrated, the switchingelement SW intersect the gate line G in two locations in each subpixelPX. Note that the switching element SW may intersect the gate line G inone location in each subpixel PX. The details about the switchingelement SW will be provided later.

A drain electrode RE is disposed in each subpixel PX. In the exampleillustrated, the drain electrode RE is located between respective twogate lines G adjacent to each other along the first direction X andbetween respective two source lines S adjacent to each other along thesecond direction Y. The drain electrode RE is electrically connected tothe switching element SW.

A pixel electrodes PE is disposed in each subpixel PX. In the exampleillustrated, the pixel electrode PE is located between respective twogate lines G adjacent to each other along the first direction X andbetween respective two source lines S adjacent to each other along thesecond direction Y. The pixel electrode PE is electrically connected tothe drain electrode RE. A potential corresponding to an image signal isapplied to the pixel electrode PE. In the example illustrated, the pixelelectrode PE has a rectangular flat plate shape without any slit or thelike, and extends substantially parallel to the respective source lineS. Note that the pixel electrode PE being a rectangular flat plate shapewithout any slit or the like is only an example, but it may be a shapewith a slit or the like, or some other shape. The conductive material CMoverlaps the drain electrode RE. The drawing illustrates a contact holeCH1 in an opening portion OP located between respective two firstelectrodes E1 adjacent to each other along the second direction Y andelectrically connecting the conductive material CM and the drainelectrode RE to the pixel electrode PE. The contact hole CH1 overlapsthe drain electrode RE, the pixel electrode PE and the conductivematerial CM. Further, a contact hole CH2 is also illustrated, whichelectrically connects the drain electrode RE and the switching elementSW to each other. Furthermore, a contact hole CH3 is illustrated, whichelectrically connects the switching element SW and the source line S toeach other.

Each first electrode E1 is disposed across a plurality of subpixels PX.In the example illustrated, the first electrodes E1 each extend in abelt-like manner along the first direction X on the X-Y plane and arearranged along the second direction Y with intervals therebetween. Inplan view, each first electrode E1 overlaps the respective source lineS, the respective pixel electrode PE and the like between respective twogate lines adjacent to each other along the second direction Y. Notethat the first electrodes E1 may extend into a plane manner along thefirst direction X and the second direction Y on the X-Y plane. Forexample, the first electrodes E1 may overlap the source lines S, thegate lines G, the light-shielding layers LS, the drain electrodes RE,the pixel electrodes PE and the like, respectively. The first electrodesE1 each are, for example, a common electrode to which a common potentialis applied.

A plurality of metal wiring lines MT (MT1, MT2, MT3, MT4, . . . ) arearranged along the first direction X with predetermined intervalstherebetween. The metal wiring lines MT (MT1, MT2, MT3, MT4, . . . )each extend along the second direction Y. Note that the metal wiringlines MT may be partially bent. The metal wiring lines MT are formed ofa metallic material such as molybdenum (Mo), an alloy mainly composed ofmolybdenum, in which metallic materials are amalgamated together, or thelike. The metal wiring lines MT overlap the source lines S, the firstelectrodes E1 and the like, respectively.

FIG. 3 is a plan view showing the second electrode E2 of the firstsubstrate SUB1 according to the first embodiment. Herein, the mainportion of the first substrate SUB1 shown in FIG. 2 is illustrated witha dotted line, an alternate long and short dash line and the like.

The first substrate SUB1 comprises second electrodes E2, spacers DPS andDXS and the like. The second electrodes E2 are each formed into alattice form on the X-Y plane. The second electrodes E2 each comprise aplurality of apertures AP. The apertures AP each extend in the seconddirection Y along the source lines S, respectively. The apertures APeach comprise two edges opposing each other along the first direction Xand not parallel (non-parallel) to each other. In the exampleillustrated, the apertures AP are each formed into a trapezoidal shape.Note that the apertures AP may be formed into a triangle form, or someother shapes than a trapezoidal shape or a triangle shape. For example,in plan view, each aperture AP overlaps the respective pixel electrodePE. Note that in plan view, the aperture AP may overlap over an entirewidth of the second electrode E2 along the second direction Y. Further,for example, in plan view, the second electrode E2 overlaps therespective source lines S in a portion between the respective twoapertures AP adjacent to each other along the first direction X.Further, in plan view, for example, the second electrode E2 overlaps therespective drain electrode RE, gate line G and the like in a portionbetween two apertures AP adjacent to each other along the seconddirection Y. The drawing illustrates a contact hole CH4 whichelectrically connects the first electrode E1 and the second electrode E2to each other. Note that the contact hole CH4 may be formed in someother location and, for example, it may be formed in the non-displayarea NDA. The second electrode E2 is, for example, a common electrode towhich a common potential equal to that of the first electrode E1 isapplied.

The spacers DXS extends further than the spacers DPS. The spacers DPSand the spacers DXS overlap the second electrode E2. In the exampleillustrated, the spacers DXS extend in the second direction Y furtherthan the spacers DPS. The spacers DXS have an elliptic shape elongatedalong the second direction Y. The spacers DPS have a circular shape.Note that the spacers DXS may extend in the first direction X furtherthan the spacer DPS. The spacers DXS need not be elliptic. Further, thespacers DPS need not be circular. The spacers DPS and the spacers DXSoverlap the second electrode E2. The spacers DPS and the spacers DXS areplaced in positions where the respective source lines S and therespective gate lines G intersect each other. The spacers DPS and thespacers DXS are placed alternately along the first direction X. Further,the spacers DPS and the spacers DXS are placed alternately along thesecond direction Y. Note that the spacers DPS and DXS need not to beplaced alternately along the first direction X and the second directionY and may be arranged with intervals of a distance by an amountcorresponding to a plurality of subpixels. Further, it suffices if atleast one side of the spacers DPS and DXS are disposed.

FIG. 4 is a cross-sectional view of the display panel PNL taken alongline A-A in FIG. 3.

The first substrate SUB1 comprises a support substrate 10, insulatinglayers 11, 12, 13, 14, 15, 16 and 17, source lines S (S1 and S2), afirst electrode E1, metal wiring lines MT (MT1 and MT2), a pixelelectrode PE, a second electrode E2, an alignment film AL1 and the like.The polarizer PL1 is provided under the support substrate 10. Note thatthe insulating layers 11 to 17 may be each expressed as an intermediateinsulating layer.

The support substrate 10 is transparent, and for example, is of aglass-made such as of borosilicate glass, but it may be of a resin-madesuch as of plastic or the like.

The insulating layers 11 to 17 are all transparent. The insulatinglayers 11 to 14, 16 and 17 each are an inorganic insulating layer, andare made of, for example, silicon nitride or silicon oxide. Theinsulating layer 15 is an organic insulating layer, and is made of, forexample, a resin such as acryl resin. The insulating layer 11 is locatedon the support substrate 10 to as be in contact with the supportsubstrate 10. The insulating layer 12 is located on the insulating layer11 so as to be in contact with the insulating layer 11. The insulatinglayer 13 is located on the insulating layer 12 so as to be in contactwith the insulating layer 12. The insulating layer 14 is located on theinsulating layer 13 so as to be in contact with the insulating layer 13.The source lines S1 and S2 are located on the insulating layer 14 so asto be in contact with the insulating layer 14. The source line S1 andthe source line S2 are arranged along the first direction X with aninterval therebetween. The insulating layer 15 are located on theinsulating layer 14 and the source lines S1 and S2 so as to be incontact with the insulating layer 14 and the source lines S1 and S2.Note that the insulating layers 11 to insulating layer 14 may bereferred to an insulating layer IL as one integrated member.

The first electrode E1 is located on the insulating layer 15 so as to bein contact with the insulating layer 15. In other words, the firstelectrode E1 is located between the insulating layer 15 and theinsulating layer 16. The first electrode E1 extends over a plurality ofpixel electrodes PE. Note that the first electrode E1 is made of, forexample, a transparent conductive material such as indium tin oxide(ITO), indium zinc oxide (IZO), indium gallium oxide (IGO) or the like.Note that it suffices if a portion of the first electrode E1, whichoverlaps the area contributing to display is transparent, and the otherportion may be of a nontransparent material. The metal wiring lines MT1and MT2 are located on the first electrode E1 so as to be in contactwith the first electrode E1. The metal wiring line MT1 is locateddirectly above the source line S1. The metal wiring line MT2 is locateddirectly above the source line S2. Note that the metal wiring lines MT1and MT2 are located between the insulating layer 15 and the firstelectrode E1 and may be in contact with the first electrode E1. Further,the metal wiring lines MT1 and MT2 may be located in a layer above theinsulating layer 16, which will be described below. The insulating layer16 is located on the first electrode E1 and the metal wiring lines MT1and MT2 so as to be in contact with the first electrode E1 and the metalwiring lines MT1 and MT2. The metal wiring lines MT (MT1 and MT2) cancontribute to, for example, prevention of mixture of colors, decreasingthe resistance of the first electrode E1 and the like.

The pixel electrodes PE are located on the insulating film 16. In theexample illustrated, a plurality of pixel electrodes PE are arrangedalong the first direction X with intervals therebetween. The pixelelectrodes PE are not located on the source line S1 or S2. The pixelelectrodes PE have a potential different from that of the firstelectrode E1. The pixel electrodes PE are made of a transparentconductive material and, for example, they are formed of the samematerial as that of the first electrode E1. Note that it suffices if aportion of the pixel electrode PE, which overlaps the area contributingto display is transparent, and the other portion may be of anontransparent material.

The insulating layer 17 are located on the insulating layer 16 and thepixel electrodes PE so as to be in contact with the insulating layer 16and the pixel electrodes PE.

The second electrode E2 is located on the insulating layer 17 so as tobe in contact with the insulating layer 17. In the example illustrated,the apertures AP and the pixel electrodes PE respectively oppose eachother through the insulating layer 17. The second electrode E2 extendsto the contact hole CH4 described above so as to be in contact with themetal wiring lines MT in the contact hole CH4. The second electrode E2is electrically connected to the first electrode E1 through the metalwiring lines MT. In the example illustrated, the second electrode E2 isin contact with the metal wiring line MT2 in the contact hole CH4. Thesecond electrode E2 is electrically connected to the first electrode E1through the metal wiring line MT2. The contact hole CH4 penetrates theinsulating layers 16 and 17 to reach the metal wiring lines MT. In theexample illustrated, the contact hole CH4 is located directly above thesource line S2, and penetrates the insulating layers 16 and 17 to reachthe metal wiring lines MT2. The second electrode E2 is made of atransparent conductive material, and is formed of, for example, the samematerial as that of the first electrode E1. Note that it suffices if aportion of the second electrode E2, which overlaps the area contributingto display is transparent, and the other portion may be of anontransparent material.

The alignment film AL1 covers the insulating layer 17 and the secondelectrode E2. The alignment film AL1 is, for example, a polyimide film.

The liquid crystal layer LC is located on the first substrate SUB1. Theliquid crystal layer LC may be of a positive type having a positivedielectric anisotropy or a negative type having a negative dielectricanisotropy.

The second substrate SUB2 is located on the liquid crystal layer LC. Thesecond substrate SUB2 comprises a support substrate 20, light-shieldinglayers BM, color filters CF, an insulating layer 21, an alignment filmAL2 and the like.

The polarizer PL2 is provided on the support substrate 20. Theabsorption axis of the polarizer PL1 and the absorption axis of thepolarizer PL2 are set to be normal to each other in plan view.

The support substrate 20 is transparent and is made of, for example,glass such as borosilicate glass, but may be made of a resin such asplastic. The light-shielding layers BM are located underneath thesupport substrate 20 so as to be in contact with the support substrate20. The light-shielding layers BM are located directly above the sourcelines S1 and S2, respectively. The color filters CF are located underthe support substrate 20 and the light-shielding layers BM so as to bein contact with the support substrate 20 and the light-shielding layersBM. In the example illustrated, the color filters CF oppose the pixelelectrode PE and are partially in contact with the light-shieldinglayers BM. The color filters CF include a red color filter, a greencolor filter, a blue color filter and the like. The color filters CF maybe located on the first substrate SUB1. The color filters CF may includefilters of four or more colors. For a pixel displaying a white color, awhite color filter may be disposed, an uncolored resin material may bedisposed or an overcoat layer OC maybe disposed without providing acolor filter.

The insulating layer 21 is located under the color filters CF so as tobe in contact with the color filters CF. The insulating layer 21 is atransparent organic insulating layer, and is made of, for example, aresin such as acryl resin. The alignment film AL2 is located under theinsulating layer 21 so as to be in contact with the insulating layer 21and cover the insulating layer 21. The alignment film AL2 is anoptical-alignment polyimide film.

FIG. 5 is a cross-sectional view of the display panel PNL taken alongline B-B in FIG. 3. Note that, here, portions different from those ofthe cross-sectional view shown in FIG. 4 will be mainly described.

The first substrate SUB1 comprises a light-shielding layer LS, aswitching element SW, a conductive material CM, a metal wiring line MT(MT2), a drain electrode RE and the like. The light-shielding layer LSis located between the support substrate 10 and the insulating layer 11so as to be in contact with an upper surface of the support substrate10. The light-shielding layer LS is made of, for example, amolybdenum-tungsten alloy. The switching element SW comprises asemiconductor layer SC. In the example illustrated, the semiconductorlayer PS is located between the insulating layer 11 and the insulatinglayer 12 so as to be in contact with an upper surface of the insulatinglayer 11. The semiconductor layer PS is made of, for example,polycrystalline silicon. Note that the semiconductor layer 15 may aswell be made of an oxide semiconductor layer. When it is made of oxidesemiconductor, the semiconductor layer PS may be placed in a positionexcept those between the insulating layer 11 and the insulating layer12. The gate electrode WG, which is a part of the gate line G (G2) islocated between the insulating layer 12 and the insulating layer 13 soas to be in contact with an upper surface of the insulating layer 12.The drain electrode RE is located between the insulating layer 14 andthe insulating layer 15 so as to be in contact with an upper surface ofthe insulating layer 14. The drain electrode RE extends to the contacthole CH2 so as to be in contact with an upper surface of thesemiconductor layer PS. The contact hole CH2 penetrates the insulatinglayers 12 to 14 to reach the semiconductor layer PS. The source line S2extends to the contact hole CH3 so as to be in contact with the uppersurface of the semiconductor layer PS. The contact hole CH3 penetratesthe insulating layers 12 to 14 to reach the semiconductor layer PS. Theconductive material CM covers the drain electrode RE in the contact holeCH1. In other words, the conductive materials CM is in contact with thedrain electrode RE in the contact hole CH1. The metal wiring line MT2 islocated between the first electrode E1 and the insulating layer 15 andthe insulating layer 16 so as to be in contact with upper surfaces ofthe first electrode E1 and the insulating layer 15. The insulating layer16 is located on the metal wiring line MT2, the insulating layer 15 andthe conductive material CM so as to be in contact with the metal wiringline MT2, the insulating layer 15 and the conductive material CM. Thepixel electrode PE extends to the contact hole CH1 so as to be incontact with the conductive material CM. In other words, the pixelelectrode PE is electrically connected to the drain electrode RE throughthe conductive material CM. The contact hole CH1 penetrates theinsulating layer 15 to reach the drain electrode RE. Note that the gateelectrode WG and the light-shielding layer LS should preferably be, forexample, electrically connected to each other and be at the samepotential.

The second substrate SUB2 comprises a light-shielding layer BM and thelike. The light-shielding layer BM is located on the gate electrode WGand the contact hole CH1 between the support substrate 20 and theinsulating layer 21.

FIG. 6 is a cross-sectional view of the display panel PNL taken alongline C-C in FIG. 3. Note that, here, portions different from those ofthe cross-sectional views shown in FIGS. 4 and 5 will be mainlydescribed.

In the example illustrated, the contact hole CH1 penetrates theinsulating layer 15 to reach the insulating layer 14. The drainelectrode RE is located between the source lines S1 and S2 arrangedalong the first direction X with an interval therebetween. The drainelectrode RE is exposed from the insulating layer 15 within the contacthole CH1. A width RW of the drain electrode RE along the first directionX is less than a width HW of the contact hole CH1 along the firstdirection X. The drain electrode RE comprises an end portion REE1 on asource line S1 side along the first direction X and an end portion REE2on a source line S2 side. The end portions REE1 and REE2 of the drainelectrode RE are each exposed from the insulating layer 15 and spacedaway from the insulating layer 15 along the first direction X. The drainelectrode RE is a three-level stacking film or the like, in which themetal layers ML1, ML2 and ML3 are stacked in order. The metal layers ML1and ML3 are formed of, for example, a metal mainly composed of titanium,molybdenum and titanium, or a metal mainly composed of molybdenum. Themetal layer ML2 is formed of, for example, aluminum or a metal mainlycomposed of aluminum. Note that it suffices if the drain electrode RE atleast includes a layer formed of aluminum or a metal mainly composed ofaluminum. Further, the drain electrode RE may be constituted by lessthan three layers, or more than three layers. The insulating layer 14includes an area AR1 exposed from the insulating layer 15 between theinsulating layer 15 and the end portion REE1 and an area AR2 exposedfrom the insulating layer 15 between the insulating layer 15 and the endportion REE2 in the contact hole CH1. The conductive material CM coversan upper surface of the drain electrode RE and the end portions REE1 andREE2 in the contact hole CH1. The conductive material CM is in contactwith the area AR1 and the area AR2. Note that it suffices if theconductive material CM covers a part which may be removed in etching orthe like during preparation of the first substrate SUB1, that is, forexample, the metal layer ML2. The conductive material CM is formed of aconductive material, for example, the same as conductive material asthat of the metal wiring lines MT or the first electrode E1. Theinsulating layer 16 is located on the insulating layer 15, the metalwiring lines MT1 and MT2 and the conductive material CM, so as to be incontact with the insulating layer 15, the metal wiring lines MT1 and MT2and the conductive material CM.

FIG. 7 is a cross-sectional view of the display panel PNL taken alongline D-D in FIG. 3. Note that, here, portions different from those ofthe cross-sectional views shown in FIGS. 4 and 6 will be mainlydescribed.

The first substrate SUB1 comprises spacers DPS and DXS and the like. Inthe example illustrated, the spacer DPS is located on the secondelectrode E2 directly above the source line S1 so as to be in contactwith the second electrode E2. The spacer DPS projects towards the secondsubstrate SUB2. The cross-section of the spacer DPS is formed into atapered shape narrowing down to a distal end portion located on thesecond substrate SUB2 side. Note that the cross-section of the spacerDPS may be formed into a shape other than the tapered shape. The spacerDXS is located on the second electrode E2 directly above the source lineS2 so as to be in contact with the second electrode E2. The spacer DXSprojects towards the second substrate SUB2. The cross-section of thespacer DXS is formed into a tapered shape narrowing down the distal endlocated on the second substrate SUB2 side. Note that the cross-sectionof the spacer DXS may be formed into a shape other than a tapered shape.The alignment film AL1 covers the second electrode E2, side surfaces ofthe spacer DPS and side surfaces of the spacer DXS.

The second substrate SUB2 comprises spacers UPS and UXS and the like. Inthe example illustrated, the spacer UPS is placed in a position shiftedfrom the spacer DPS along the first direction X. The spacer UPS islocated under the insulating layer 21 directly above the source line S1so as to be in contact with the insulating layer 21. The spacer UPSprojects towards the first substrate SUB1. The cross-section of thespacer UPS is formed into a tapered shape narrowing down towards thedistal end located on the first substrate SUB1 side. Note that thecross-section of the spacer UPS may be formed into a shape other thanthe tapered shape. When a force is applied to the first substrate SUB1and the second substrate SUB2 along the first direction X, the spacerDPS and the spacer UPS engage with each other, thereby inhibiting thefirst substrate SUB1 and the second substrate SUB2 shifting in the firstdirection X. The spacer UXS is located under the insulating layer 21directly above the source line S2 so as to be in contact with theinsulating layer 21. The spacer UXS projects towards the first substrateSUB1. The cross-section of the spacer UXS is formed into a tapered shapenarrowing down towards the distal end portion located on the firstsubstrate SUB1 side. Note that the cross-section of the spacer UXS maybe formed into a shape other than the tapered shape. The distal endportion of the spacer UXS is in contact with the distal end portion ofthe spacer DXS. The spacer UXS extends further than the spacer DXS inthe first direction X. Therefore, even if a force is applied to thefirst substrate SUB1 and the second substrate SUB2 in the firstdirection X to shift the first substrate SUB1 and the second substrateSUB2 in the first direction X, it is possible to inhibit the spacer UXSfrom disengaging from the spacer DXS.

According to this embodiment, the display device DSP comprises aninsulating layer 14, an insulating layer 15 located on the insulatinglayer 14 and comprising a contact hole CH1, a drain electrode RE locatedon the insulating layer 14 and exposed from the insulating layer 15within the contact hole CH1, a first electrode E1 located on theinsulating layer 15, metal wiring lines MT located on the insulatinglayer 15 and the first electrode E1 and in contact with the firstelectrode E1, and a conductive material CM covering the drain electrodeRE within the contact hole CH1. In the drain electrode RE, the metallayers ML1, ML2 and ML3 are stacked one on another. The metal layer ML2is formed of, for example, aluminum or a metal mainly composed aluminum.The drain electrode RE includes an end portion REE1 and an end portionREE2. The end portions REE1 and REE2 are each spaced apart from theinsulating layer 15 along the first direction X. The conductive materialCM is formed of, for example, the same material as that of the metalwiring lines MT or the first electrode E1. The conductive material CMcovers the upper surface of the drain electrode RE and the end portionsREE1 and REE2 within the contact hole CH1. Therefore, in themanufacturing process of the display device DSP, for example, in a stepof etching metal wiring lines MT, it is possible to inhibit the drainelectrode RE, for example, the metal layer ML2 thereof, from beingremoved by the etching or the like. Thus, a display device DSP with animproved reliability can be provided.

Note that the display device DSP is limited to the configuration exampledescribed above, but may be of a configuration that the first electrodeE1 and the second electrode E2 are replaced by pixel electrodes and thepixel electrodes PE are replaced by electrodes of a common potential.

Next, other configuration examples of the first embodiment will bedescribed with reference to FIGS. 8 to 10, respectively. In the otherconfiguration examples of the first embodiment described below, portionssimilar to those of the first embodiment are denoted by the samereference numerals and detailed explanation thereof is omitted, andportions different from those of the above-explained embodiment will beparticularly explained in detail. Note that, in the other configurationexamples, an advantageous effect similar to that of the above-describedfirst embodiment can be also obtained.

The configuration example shown in FIG. 8 is different from the exampleof FIG. 6 in the structure of the conductive material CM. In theconductive material CM, a first conductive layer CML1 and a secondconductive layer CML2 are stacked in this order. The first conductivelayer CML1 is formed of, for example, the same material as that of thefirst electrode E1. The second conductive layer CML2 is formed of, forexample, the same material as that of the metal wiring lines MT. In thisconfiguration example as well, an advantageous effect similar to that ofthe first embodiment can be obtained.

The configuration example shown in FIG. 9 is different from that of theexample of FIG. 6 in that the first substrate SUB1 does not comprisemetal wiring lines MT. The insulating layer 16 located on the insulatinglayer 15 so as to be in contact with the insulating layer 15. Theconductive materials CM is formed of, for example, the same material asthat of the first electrode E1. In this configuration example as well,an advantageous effect similar to that of the first embodiment can beobtained.

The configuration example shown in FIG. 10 is different from that of theexample of FIG. 6 in the structure of the first substrate SUB1. Thefirst substrate SUB1 does not comprise the insulating layer 17 or thesecond electrode E2. The first alignment film AL1 covers the insulatinglayer 16 and the pixel electrodes PE. In this configuration example aswell, an advantageous effect similar to that of the first embodiment canbe obtained.

While certain embodiments have been described, these embodiments havebeen presented by way of example only, and are not intended to limit thescope of the inventions. Indeed, the novel embodiments described hereinmay be embodied in a variety of other forms; furthermore, variousomissions, substitutions and changes in the form of the embodimentsdescribed herein may be made without departing from the spirit of theinventions. The accompanying claims and their equivalents are intendedto cover such forms or modifications as would fall within the scope andspirit of the inventions.

What is claimed is:
 1. A display device comprising: a first insulatinglayer; a first source line and a second source line located on the firstinsulating layer and arranged with an interval therebetween; an organicinsulating layer located on the first insulating layer, the first sourceline and the second source line and comprising a contact hole; a drainelectrode located on the first insulating layer between the first sourceline and the second source line and exposed from the organic insulatinglayer in the contact hole; a conductive material covering the drainelectrode in the contact hole; a second insulating layer located on theorganic insulating layer; and a pixel electrode located above the secondinsulating layer and in the contact hole, and in direct contact with theconductive material and electrically connected to the drain electrode,wherein the conductive material being in contact with the firstinsulating layer exposed from the organic insulating layer between theorganic insulating layer and the drain electrode in the contact hole. 2.The display device of claim 1, wherein the first insulating layercomprises a first area exposed from the organic insulating layer betweenthe organic insulating layer and a first end portion of the drainelectrode on a side of the first source line side and a second areaexposed from the organic insulating layer between the organic insulatinglayer and a second end portion of the drain electrode on a side of thesecond source line, and the conductive material is in contact with thefirst area and the second area.
 3. The display device of claim 1,further comprising: a first electrode located between the organicinsulating layer and the second insulating layer; a first metal wiringline overlapping the first source line and in contact with the firstelectrode; and a second metal wiring line overlapping the second sourceline and in contact with the first electrode.
 4. The display device ofclaim 3, wherein the conductive material is formed of a first materialsame as that of the first electrode.
 5. The display device of claim 3,wherein the conductive material is formed of a second material same asthat of the first metal wiring line and the second metal wiring line. 6.The display device of claim 3, wherein the conductive material is formedby staking the second material same as that of the first metal wiringline and the second metal wiring line on the first material same as thatof the first electrode.
 7. The display device of claim 3, wherein thefirst metal wiring line and the second metal wiring line are locatedabove the first electrode.
 8. The display device of claim 3, furthercomprising: a second electrode located on the pixel electrode andelectrically connected to the first electrode.
 9. The display device ofclaim 1, wherein the pixel electrode is in contact with an upper surfaceof the conductive material without being in contact with the drainelectrode.
 10. The display device of claim 1, wherein the drainelectrode contains aluminum.
 11. A display device comprising: a firstinsulating layer; a first source line and a second source line locatedon the first insulating layer and arranged with an intervaltherebetween; an organic insulating layer located on the firstinsulating layer, the first source line and the second source line andcomprising a contact hole; a drain electrode located on the firstinsulating layer between the first source line and the second sourceline and comprising a first end portion on a side of the first sourceline exposed from the organic insulating layer in the contact hole and asecond end portion on a side of the second source line; a conductivematerial covering the first end portion and the second end portion inthe contact hole; a second insulating layer located on the organicinsulating layer; and a pixel electrode located on the second insulatinglayer and in the contact hole, in direct contact with the conductivematerial, and electrically connected to the drain electrode.
 12. Thedisplay device of claim 11, further comprising: a first electrodelocated between the organic insulating layer and the second insulatinglayer, wherein the conductive material is formed of a first materialsame as that of the first electrode.
 13. The display device of claim 11,further comprising: a first electrode located between the organicinsulating layer and the second insulating layer, and a first metalwiring line overlapping the first source line and in contact with thefirst electrode, wherein the conductive material is formed of a secondmaterial same as that of the first metal wiring line.
 14. The displaydevice of claim 11, further comprising: a first electrode locatedbetween the organic insulating layer and the second insulating layer,and a first metal wiring line overlapping the first source line and incontact with the first electrode, wherein the conductive materialcomprises the first material same as that of the first electrode and asecond material same as that of the first metal wiring line stacking oneon another.
 15. A display device comprising: a first insulating layer; afirst source line and a second source line located on the firstinsulating layer and arranged with an interval therebetween; an organicinsulating layer located on the first insulating layer, the first sourceline and the second source line and comprising a contact hole; a drainelectrode located on the first insulating layer between the first sourceline and the second source line and exposed from the organic insulatinglayer in the contact hole; a conductive material covering the drainelectrode in the contact hole; a second insulating layer located on theorganic insulating layer; a pixel electrode located on the secondinsulating layer and electrically connected to the drain electrode; afirst electrode located between the organic insulating layer and thesecond insulating layer; and a first metal wiring line overlapping thefirst source line and in contact with the first electrode, theconductive material being in contact with the first insulating layerexposed from the organic insulating layer between the organic insulatinglayer and the drain electrode in the contact hole, and the conductingmaterial containing at least one of a first material same as that of thefirst electrode and a second material same as that of the first metalwiring line.
 16. The display device of claim 15, wherein the conductivematerial contains the first material same as that of the first electrodeand the second material same as that of the first metal wiring linestacking one on another.